Opisthobranch molluscs such as Aplysia have proven highly useful for a variety of neurobiological and behavioral studies including studies of the development of the nervous system, the biophysical properties of neurons, their patterns of interconnections, their roles in behavior and their modification by learning. A major limitation to the more extensive use of these organisms has been the inability to culture the animals in large quantities. This program of research is designed to develop simple and effective techniques for rearing and maintaining of Aplysia in both inland and marine laboratories. Specifically we plan to develop xenic techniques for carrying large numbers of larvae through metamorphosis and into reproductive maturity and to explore well-defined artificial seawater media and substitute these for natural seawater.